A Wearable All-Gel Multimodal Cutaneous Sensor Enabling Simultaneous Single-Site Monitoring of Cardiac-Related Biophysical Signals

The human cutaneous sensory organ is a highly evolved biosensor that is efficient, sensitive, selective, and adaptable. Recently, with the development of various materials and structures inspired by sensory organs, artificial cutaneous sensors have been widely studied. In this study, the acquisition of biophysical signals is demonstrated at one point on the body using a wearable all-gel-integrated multimodal sensor composed of four element sensors, inspired by the slow/rapid adapting functions of the skin sensory receptors. The gel-type sensors ensure flexibility, compactness, portability, adherence, and integrity. The wearable all-gel multimodal sensor is easily attached to the wrist and simultaneously gathers blood pressure (BP), electrocardiogram (ECG), electromyogram (EMG), and mechanomyogram (MMG) signals related to cardiac and muscle health. Human activity causes muscle contraction, which affects blood flow; therefore, the relationship between the muscle and heart is crucial for screening and predicting heart health. Cardiac health is monitored by obtaining the two types of phase time differences (i.e., Δt_be: BP and ECG, Δt_em: ECG and MMG) generated during muscle movement. The suggested multimodal sensor has potential applicability in monitoring biophysical conditions and diagnosing cardiac-related health problems.